Conventionally, in order to implement advanced automation in a plant, a factory or the like, DCSs (distributed control systems) have been built, in which on-site devices such as measuring instruments and actuators, which are known as field devices, are connected via a communication means to a control apparatus that controls them. Although almost all of the communication systems forming the basis for such distributed control systems have been ones that communicate via cable, in recent years implementations that communicate wirelessly in conformance with wireless communication standards such as ISA 100.11a have appeared.
Communication systems conforming to the above-noted ISA 100.11a wireless communication standard are generally classified into field devices capable of wireless communication (wireless field devices), wireless gateways, and host apparatuses. A wireless gateway forms a wireless communication network with wireless field devices, and functions so as to control the operation of wireless field devices that belong to the wireless communication network and collect various data obtained by the wireless field devices. A host apparatus is connected to a wireless gateway via a communication line and manages wireless field devices via the wireless gateway.
In this case, in order to enable the above-noted wireless field device to join a wireless communication network, it is necessary to perform a task known as provisioning, which sets device information with respect to a wireless field device that is to join, as well as to perform a task of registration into the wireless gateway to be joined device information that identifies the wireless field device which has been the subject of the provisioning. The provisioning with respect to the wireless field device is performed, for example, by a worker, using a device known as a provisioning device, which is capable of infrared communication between itself and the wireless field device, and the task of registering into the wireless gateway is performed, for example, by an administrator, using the above-noted host apparatus.
A wireless field device in which device information coinciding with the device information registered into the wireless gateway is set is permitted to join the wireless communication network, and a wireless field device in which other device information is set is refused from joining the wireless communication network, by the wireless gateway. Although it is from a different field of art, Patent Document 1 noted below discloses art for controlling the transmission and reception of a temporary message between mobile communication terminals, which has the meaning of requesting execution of prescribed processing, in accordance with the position of a communication terminal.